Correlation Between Anterior Cruciate Ligament Injury And Anatomical Parameters Of Distal Femur And Proximal Tibia

Background:There is a correlation between the anterior cruciate ligament(ACL)injury and the anatomical parameters of the knee joint.However,at present,most studies focus on the qualitative research of ACL injury and some parameters,while the quantitative research on the multiple factors of ACL injury is rare.The objective of this study was to investigate multiple morphological features of distal femur and proximal tibia the on MRI in patients with and without ACL injury to evaluate whether there are certain variables that confer a higher risk for an ACL injury,to explore the risk factors in the knee joint anatomy contribute to the ACL injury and the parameters differences between different gender,to evaluate the correlation between ACL injury and the distal femoral and proximal tibia anatomic parameters,trying to find the independent risk factors and the cause of ACL injury.It will provide theoretical basis for the research on the mechanism of ACL injury,and also basis and reference for the prevention and treatment of ACL injury.MethodsThis is a retrospective case-control study,we compared multiple morphological features of distal femur and proximal tibia on MRI in patients with and without ACL injury.These features include Femoral intercondylar notch width,Femoral notch width index,Intercondylar notch height,Intercondylar notch height index,Tibial eminence width,Tibial platform width,Tibial eminence width index,Medial tibial slope,Medial menisccal slope,Lateral tibial slope,Lateral meniscal slope,Medial meniscus-to-tibia slope difference,Lateralmeniscus-to-tibia slope difference,Medial-to-lateral tibial slope difference,Medial-to-lateral meniscal slope difference,ACL concave length,ACL concave length index.The measurement of these parameters was conduceted by two independent orthopedists,the reliability of these measurement was asseseed by Intraclass Correlations coefficient and Interclass Correlations coefficient.The difference of the datas between two groups was assessed by the analysis of the SPSS24.And then finding out which factors have statistical significance in the two groups,obtaining the regression coefficient of related risk factors by LOGISTIC regression analysis,so as to judge the independent influence of each risk factor on ACL injury and find out the quantitative impact of these factors on ACL injury.ResultsCompared with the control group,in the case group,the intercondylar notch width and the intercondylar notch width index is decreased,the coronal angle of the intercondylar notch is decreased,the tibial eminence width and the eminence width index is decreased,the medial tibial slope,medial menisccal slope,lateral tibial slope and the lateral meniscal slope is increased,and Medial meniscus-to-tibia slope difference,Lateral meniscus-to-tibia slope difference,Medial-to-lateral tibial slope difference,Medial-to-lateral meniscal slope differenceare all decreased in the case group.And the ACL concave length is decreased well as the ACL concave length index in the case group.Similar resaults was found in the gender-specific case and control groups.All the difference is statistically significant(p<0.05).In LOGISTIC regression,only the intercondylar notch width index,Medial menisccal slope,Lateral meniscal slope,ACL concave length index were incorporated into the regression equation.Take the contrast of case group and control group as an example,for every 1% increase in ACL small concave,the risk of ACL injurywill be reduced by 22.8%,each increased 1°in the medial meniscal slope could contribute to ACL injury risk increase by 36.1%,and the lateral meniscal slope increase in each 1°,ACL injury risk will increase by119.6%,and each 1% increase of the intercondylar notch width index,the risk of ACL injury will be reduced by 37.3%.similar resauts was found in the case group and control group among gender-specific samples.Compared male samples with female samples,there were statistical differences between different sexes in height,weight,intercondylar notch width,bicondyle width,intercondylar notch height,tibial eminence width,tibial width and ACL concave length(p<0.05),but BMI,intercondylar notch width index,intercondylar notch height index,tibial eminence index and the ACL concave index were no statistical difference(p>0.05).Thus,male and female anatomical parameters are compatible with their own body shape,the parameters comparison between the two genders can not directly compare the numerical size,but to compare the proportion of this parameter.In terms of results,there was no significant difference in the corrected anatomical parameters of the distal femur and the proximal tibia between male and female after the adaptation to the body shap(p>0.05).In male samples,the case group and the control group were statistic different in the intercondylar notch width,intercondylar notch width index,tibial eminence width,tibial eminence width index,medial tibial slope,medial menisccal slope,lateral tibial slope,lateral meniscal slope,medial meniscus-to-tibia slope difference,lateral meniscus-to-tibia slope difference,medial-to-lateral tibial slope difference,medial-to-lateral meniscal slope difference,ACL concave length and ACL concave length index(p<0.05).But only the intercondylar notch width index,ACL concave length index,medial menisccal slope,lateral meniscal slope were incorporated into the regression equation.And for every 1% increase in the intercondylar notch width index,the risk of ACL injury will be reduced by 30.8%,every 1% increase in the ACL concave length index,the risk of ACL injury will be reduced by 27%,every increased1°in the medial meniscal slope,the risk of ACL injury will be increased by 61.9%,and when the lateral meniscal slope is increased by 1°,the risk of ACL injury will increase by 86.1%.In female samples,the case group and the control group were statisticly different in the intercondylar notch width,the intercondylar notch width index,the coronal angle of intercondylar notch,the tibial eminence width,the tibial eminence width index,the lateral tibial slope,lateral meniscal slope.However,in LOGISTIC regression analysis,no statistical differences were found in these anatomical parameters,small sample volume may be the cause of the result.ConclusionThis study found that ACL injury risk factors were attributed to decreased value of the intercondylar notch width,the intercondylar notch width index,the coronal angle of the intercondylar notch,the tibial eminence width,the tibial eminence width index,the increased value of the medial tibial slope,the medial meniscal slope,the lateral tibial slope,the lateral meniscal slope.The medial meniscus-to-tibia slope difference,the lateral meniscus-to-tibia slope difference,the medial-to-lateral tibial slope difference,and the medial-to-lateral meniscal slope difference also decreased in the case group,ACL concave lengthand the ACL concave length index is decreased,among all the statisticsly different parameters,the intercondylar notch width index,the medial meniscal slope,the lateral meniscal slope,and the ACL concave length index are independent risk factors of ACL injury.There may be the reason:Too small intercondylar notch width index may lead to impingement of the ligament and intercondylar notch bone ridge,long-time repeated friction leads to ACL injury,when the intercondylar notch width index is less than 27% in patients with ACL injury and the surgical reconstruction is necessary,the intercondylar notch plasty should be considered during the reconstruction process,In order to reduce the chance of re-injury after reconstruction.Excessive posterior slope of the medial and lateral meniscus may result in shifting and rolling backward of the medial and lateral femoral condyle relatively to the medial and lateral meniscus,and then increasing ACL tension and ACL injury risk.So patients with meniscus injury,especially the anterior and posterior root of meniscus,it is recommended to carry out meniscus suture as soon as possible,and it is not recommended to perform meniscus resection,possibly because the posterior angle of meniscus is damaged in ACL injury or resection cases,which will increase the meniscus posterior slope or back shift,thus increasing the femur relative to the tibia and rolling back,increase the tension of the ACL and increase the risk of ACL injury.The decreased index of ACL concave length may be related to the decreased cross-sectional area of ACL ligament,and when the cross-sectional area from tibial attachment to middle of ligament is small,the strenth of ACL is decreased,the maximum tension that ACL can withstand is decreased,so it is more likely to lead to ACL injury.Therefore,in these cases,when the ACL ligament is reconstructed,it is necessary to ensure that the graft is thick enough to withstand a certain amount of tension.